Fw: Children may get too much radiation in CT scan

["JOHN JACOBUS" <JENDAY1@email.msn.com>]

You wrote:
. . .
(2) The term "overdoses" always irks me. Since medical radiation
exposure is basically not regulated, are these researchers taking
license in comparing the CT scan dose to the permissible dose to
minors, as found in 10CFR20? A minor is permitted to receive 500
mrem/year (5.00 mSv/year). Is any dose  above this value what
they deem to be an over-exposure?
. . .

Title 10 Code of Federal Regulations has no statutory control over CT
exposures, only for exposures from material licensed by the Nuclear
Regulatory Commission.  I do not know of any regulatory agencies, state or
federal, that control the exposures patients  received in the course of
medical examinations.  Physicians order scans, and technicians perform the
studies.

The issue the article highlights is that some facilities are using
techniques that give higher doses to patients than necessary to achieve the
desired image.  At the NCRP meeting in 1999 there was a presentor who
discussed the problem of high patient exposures from CT or any digitized
imaging system.  With film, you darken the film if it received too
much radiation.  Of course, the patient receives orders of magnitude more
dose than the film.
With digital systems, you can adjust the image to get an acceptable,
diagnostic image.  Exposure to the receptor is not longer a limiting factor
for exposure, unless it is too low.

I think good medical practice and radiation safey should dictate that no
more radiation than necessary should be used to get the image you need.  It
also
saves wear and tear on the equipment.

-- John

John Jacobus, MS, CHP
Health Physicist
3050 Traymore Lane
Bowie, MD 20715-2024
jenday1@email.msn.com (H)





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